Multi Regime combustion under technically relevant conditions: Experimental and numerical investigation of thermo-chemical states and flame structures

技术相关条件下的多态燃烧：热化学状态和火焰结构的实验和数值研究

• 批准号: 325144795
• 负责人: Professor Dr. Andreas Dreizler
• 金额: --
• 依托单位: Fachgebiet Reaktive Strömungen und Messtechnik (RSM)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2016
• 资助国家: 德国
• 起止时间: 2015-12-31 至 2020-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/325144795?language=en
• 关键词: Multi; Regime; combustion; under; technically

Turbulent combustion can be classified as premixed or non-premixed. These two limiting cases have been studied extensively and mathematical models have been developed for premixed and non-premixed flames. Besides these two limits, stratified and partially premixed flames have also been investigated, using however either premixed or non-premixed models. Modeling of flames, which can neither be categorized as premixed nor as non-premixed (multi regime combustion), is an open scientific issue. Multi regime combustion can be found in a variety of practical systems such as gas turbines or engines.Recent studies have shown that the local flame structures in multi regime combustion can differ significantly from both limiting cases. Currently, no suitable LES model exists that is capable of describing both the premixed/non-premixed limits as well as the intermediate states. Furthermore, no experimental reference data set is available, where the different flame structures are realized through systematic variations of boundary conditions. Therefore, the objective of this study is a systematic experimental and numerical investigation, model development and analysis of multi regime combustion.The research project consists of 3 work packages (AP). In the experimental work package AP1 a burner with well-defined boundary conditions for generating the reference data will be developed. Flame stabilization is achieved through recirculation zones such that the combustion regime can be controlled by varying the inlet conditions both in velocity and stoichiometry. The cold flow and mixture field will be characterized with high-speed PIV and Raman spectroscopy. For the combusting cases, the thermo-chemical state will be recorded with Raman/Rayleigh scattering. Furthermore, simultaneous quantitative OH-LIF measurements will be carried out for the first time.In the numerical AP2 two-dimensional flamelet equations (mixture fraction and progress variable formulation) will be solved. For a subsequent usage in LES and for comparison with the experiments a novel parameterization will be developed based on additional progress variables instead of scalar dissipation rates. Initially, the model will be tested against fully resolved solutions of a triple flame. For the LES flamelet tables, statistical information from experimentally determined joint probability density functions will be analyzed and integrated.In AP3 experimental and numerical methods will be combined. As a first step the results from the LES will be validated. Subsequently, the identification of combustion regimes, the characterization of the local thermo-chemical state and the flame structure will be carried out. This analysis will be based on a novel gradient-free flame identification and flame characterization method developed in this project. The project will be carried out in close collaboration with Prof. Vervisch as Mercator fellow.

湍流燃烧可以归类为预混合或未构造。已经对这两个限制案例进行了广泛的研究，并为预混合和未塑造的火焰开发了数学模型。除了这两个限制外，还使用了预混合或未建立的模型，还研究了分层和部分预混合的火焰。火焰的建模既不能被归类为预混合，也不能被归类为未经原理（多政权燃烧），这是一个开放的科学问题。在多种实用系统（例如燃气轮机或发动机）中可以找到多种状态燃烧。续研究表明，多政权燃烧中的局部火焰结构与这两种限制案例都可能有很大差异。当前，尚无合适的LES模型，能够描述预混合/未建立的限制以及中间状态。此外，没有实验参考数据集可用，其中通过系统条件的系统变化来实现不同的火焰结构。因此，这项研究的目的是进行系统的实验和数值研究，模型开发和多政权燃烧的分析。研究项目由3个工作包（AP）组成。在实验工作包中，将开发具有定义明确的边界条件的燃烧器，以生成参考数据。火焰稳定是通过再循环区域实现的，从而可以通过改变速度和化学计量的进气条件来控制燃烧方案。冷流量和混合物场将通过高速PIV和拉曼光谱进行表征。对于燃烧的情况，将使用拉曼/雷利散射记录热化学状态。此外，将首次进行同时定量的OH-LIF测量。在数值AP2中，将求解二维火焰方程（混合分数和进度变量配方）。对于随后在LE中的用法并与实验进行比较，将根据其他进度变量而不是标量耗散率开发新的参数化。最初，该模型将针对三重火焰的完全解决的解决方案进行测试。对于LES Flamelet表，将分析和集成实验确定的关节概率密度函数的统计信息。在AP3实验和数值方法中将合并。作为第一步，LES的结果将得到验证。随后，将执行燃烧状态，局部热化学状态和火焰结构的表征。该分析将基于本项目中开发的新型无梯度识别和火焰表征方法。该项目将与Vervisch教授密切合作，担任Mercator研究员。